1. Technical Field
The present invention relates generally to high-performance, fault-tolerant web content delivery.
2. Description of the Related Art
It is known in the prior art to distribute media-rich web objects away from busy home sites to a network of content servers located across multiple major Internet backbone networks. One such content delivery service (CDS) is known as FreeFlow, which is available from Akamai Technologies, Inc. of Cambridge, Mass. Akamai operates a global content delivery network (CDN) comprising a large number of distributed content servers, network mapping servers, and associated mechanisms to track reporting and administration of its content delivery service. The Akamai content servers are typically located at edge-of-network access points such as Internet Points-of-Presence (POPs).
In operation of the FreeFlow CDS, a software tool is used to tag embedded web page objects, such as graphics and images, for delivery via the CDN. Typically, the objects are tagged by transforming web page Uniform Resource Locators (URLs) that identify those objects. The objects identified by the modified URLs are then hosted on the CDN content servers. In a typical user interaction with a FreeFlow-enabled web site, the user's browser sends a request for a web page to the site. In response, the web site returns the page markup language (e.g., HTML) code as usual, except that the embedded object URLs have been modified to point to the content delivery service. As a result, the browser next requests and tries to obtain the media-rich embedded objects from an optimally-located delivery service server, instead of from the content provider's site. The above-described web content delivery service provides significant advantages, namely, faster downloads for end-users, reduced load on the home site, flash crowd protection, easier web site management and infrastructure scaling, and the ability to distribute media-rich objects effectively.
There are a number of third party vendors of HTTP caches. These caches would be quite useful in a content delivery service as they can cache and serve content that has been tagged for delivery by the CDS. While it would be desirable to enable third party caches to become content servers in the CDN, complications arise because the CDS does not have a priori knowledge of the locations and configurations of these machines, nor does it have administrative access to them at runtime. Thus, it has not been possible to enable third party caches to readily “join” a CDN. The present invention addresses this need in the content delivery art.